Improvement in machines for separating and treating ores



STEPHEN KROM, OF NEW YORK, N. Y.

IMPROVEMENT IN MACHINES FOR SEPARATING AND TREATING ORES.

Specification forming part of Letters Patent No. 121,526, dated December5, 1871.

To all whom it may concern:

Beit known that I, STEPHEN R. KRoM, ofthe city and county of New York,State of New York, have invented certain new and useful Improvements inSeparating-Machines for the Treatment of Ores and analogous material, ofwhich the following is a specification:

The improved machine is intended, like those described in former patentsto me, to separate material according to its specific gravity, and, to agreat extent, independently of the varying size of the particles. Itoperates like those by the aid of intermittent jets of air blown upwardthrough a layer of the mixed material, which travels slowly along on aperforated bed.

The improvements are intended to increase the efficiency and perfectionof the separation, and to overcome the difliculties which have beenheretofore experienced.

One of the difficulties has been a tendency of the air to blow upwardthrough or past the layer of material at the edges. The air seems tolind an easier passage along the smooth side of a gate oven-closingsurface than through the more sinuous spaces through the center of thesame layer. It is a frequent occurrence to find the material along eachedge blown up more violently than upon the other portions of the layer.I have overcome this by simple and novel means; have devised means forincreasing the suddenness with which the air is thrown up through thebed, have arranged to interpose a valve be- L tween a continuous blowingmeans and the bed in a position practically nearer to the bed than inany former machine; have devised means for closing the valve morepromptly7 and completely, have provided a capacious chamber for the a-irclose to the valve, which serves to equalize the ilow of the air fromthe blowing means and increase the vigor of the intermittent jets; havedevised a new form for the delivery passage or passages which graduatesthe delivery from the different portions ofthe ore-bed; have providedmeans for more delicate and convenient variations of the rate ofdelivery; have provided duplicate deliveries separately controllable,and have provided a duplicate bed and a duplicate separa-tion in thevsame machine.

I will proceed to describe what I consider the best means of carryingout the invention in its several parts.

The accompanying drawing forms a part of this speciiication.

Figure l is an end elevation of an entire machine. Fig. 2 is across-section of the same. Fig. 3 is a portion of a longitudinalsection, and Fig. 4 is a front view.

The above gures show what I esteem the simplest form of theconstruction, and, on some accounts, the best. The succeeding figuresshovsT some of the details and some very desirable modifications.

Fig. 5 is a cross-section of a form with a bed in two parts, onereceiving the light matter passing off from the other. Fig. 6 presents asection of the bed, showing a barred or hollow-grated construction,which I prefer for all the modifications. Fig. 7 shows a controllingvalve in such barred bed. Fig. 8 is a view ofthe same at right angles toFig. 7. Fig. 9 shows the gearing at the end of the machine to be usedwhen two separate delivering-rolls are employed, as in Fig. 5. Fig. 1()shows a form in which the two parts of the divided bed are placed atdifferent levels, with the other parts correspondingly arranged. Fig. 11is an end view, and shows a diiferent inode of operating the valve whichadmits puffs of air. Fig. 12 is a corresponding cross-section, and Fig.13 is a view of certain parts of the mechanism detached.

Similar letters of reference indicate like parts in all the figures.

A A is a fixed frame-work. T is a main drivingshaft, and C is atrip-wheel fixed thereon, which operates the valve for inducing thepuffs, and also the pawl for operating the delivery. D is the valve. Itis fixed on arms D1, which extend from a rockin g-shaft, d, governed byan arm, D2, which is IiXed on an overhanging end of the shaft, as willappear further ou. I is the orebed. It is constructed of hollow bars ortubes of rectangular sides, as shown in Fig. 6, and as set forth indetail in the patent issued to me dated the 4th day of August, 1868. Theseveral tubes or bars are composed of wiregauze or analogous lineopen-work material, extending' along lengthwise of the travel of thematerial. These open-work bars thus form hollows or channels in whichthe air ilows freely along, and passes upward and outward laterallythrough the perforations, and the lighter material, forming the stratumabove, works along at the top,

while its heaviest particles, descending by gravity, pass through thespaces between the bars. The particles, after descending past the bars,close together and form a dense body of granular particles. Thedescending or sinking of the heavy particles is controlled by thedischarging device.

The air for my puffs is furnished by a blower', air-pump, or otherefficient means for inducing a suiiciently-stron g pressure. The blowingmeans, not represented, forces the air through a pipe, U', into acapacious chamber, U, which is near the bed I. The valve D controls thepassages between this chamber U and the interiors of the several hollowbars in the bed. The valve is a long iiat strip of wood or metal, madetrue and straight on the upper surface and iitted air-tight to thevalve-seat D3, and preferably faced with rubber or analogous softmaterial, which allows it to strike suddenly at rapidly-recurringintervals without injury, and comparatively noiselessly. The valve opensdownward, admitting compressed air from the reservoir U into the space Pimmediately above the valve, which is merely a channel extending alongthe ends of the hollow bars in the bed, and, without any room forexpansion and softening of the shock, darts directly into the hollowbars and upward and outward therefrom through the perforations. Theconstruction provides the smallest possible space between the valve andthe hollow bars of the bed. The reservoir U, by the elasticity of theair therein, equalizes the action, so that the flow through the passageU may be constant or nearly so, while the discharge through the valve Dis opened and closed at rapidly-recurring intervals, preferably at therate of four hundred and fifty to five hundred or even more per minute.

I open the valve by the percussion of a moving weight, and make theaction thereby unusually rapid and efiicent. The several projections onthe trip-wheel U alternately depress and liberate a roller, G, whichturns on a pin iixed in the hammer' F. This latter slides in the lixedguides a a so that it can move only in a vertical direction, and ispressed upward with a graduated force by means of the spiral spring E,which surrounds its lower end and acts against a collar fixed invariable positions by means of a nut, c, and a jam-nut which holds itsecurely in position. lVhen it is desired to increase the force of theascent of the hammer F it is necessary simply to unscrew the jam-nut anddepress the nut e, then tighten the jam-nut again. The upper end of thehammer F is provided with a cushion, j', of leather, raw-hide, rubber,wood, or any substance which allows the hammer to impart its velocity tothe lever D2 with slight noise. At each passage of a tooth on thetrip-wheel C the hammer rises actively, and, striking the lever D2,opens the valve D in opposition to the tension of a spring, O, whichimmediately afterward closes the valve D again. There is an adjustablestop, A, correspondinglycushioned, and adjustable by means of ascrew-thread and jam-nut, as will be readily understood, which arreststhe motion of the lever D2 when the hammer tends from any valve, iseifected with sufficient torce and rapidity by the tension of the springO, which is adjustable in .force by means of the nuts O1 ()2 on thethreaded rod represented. Vhen it is desired to close the valve D morerapidly the nuts O1 O2 are screwed upward on the rod, thereby causingthe spring O to be drawn down with more force. It will be understoodthat the nuts Ol O2 act on the opposite faces of a suitable boss or armon the frame-work A of the machine.

The dischargi11g-passage J is peculiarly formed to equalize the descentof the heavy material and make it correspond with the quantity of heavymaterial which is separated along each portion of the hollow bars of thebed` The heavy matter will generally become separated as soon as thematerial descends from the hopper and reaches the bed I, and I have informer machines made my discharge for the heavy particles more rapidnear the hopper M or gate N; but I now consider it an advantage to makethe most rapid descent of the heavy particles near or at the front gateK, for the reason that it obviates the danger of ore accumulating at thefront gate K and being lost in the overflow of tailings. In other words,l have discovered that it is desirable to discharge more rapidly fromthe front or advanced portions ofthe bed than from the back or iirstportions thereof; and I effect these ends by giving an oblique form tothe back of the dischargingpassage, so that the material is largelysupported by the bounding walls of the passage on that side, while it isfree to descend vertically on the front side. The above is the formshown in Fig. 2; but it is desirable to still further draw downward uponthe heavy material at the extreme front edge of the bed. I effect thisimport-ant end by making the front side of the passage to overhang, asshown at H in Figs. 5 and l2. Fig. l2 shows the most complete form ofthese parts, the back side of the passage being inclined, as shown, soas to partially support the material, the middle of the passage beingleft free and the front being overhung. By this form there is more spacefor the particles to descend for a given area at the extreme frqnt edgethan at any other point therein, and it follows that the material fromthe middle and back is compelled to tumble forward and fill that space.The resistance from the mutual friction ol' the granular particles tendsto hold back on the central portions and back portions` in addition tothe retardation due to the oblique position of the back, while theparticles at the immediate front of the passage experience none of thisretardation and descend with the most freedom. The descent, therefore,is unusually ra-pid at the front. In the form of the apparatus shown inFigs. 2 and l2 a single disch arging-wheel, L, controls the dischargefrom the passage from the entire bed. In Fig. 5 I have represented whatI esteem the preferable form, particularly for some kinds of material.In that gure the bed is divided into two distinct portions, and thereare two discharging-passages for V heavy material and two wheels L,which, it will be understood, are turned by means which may beseparately controlled, if desired; but I have preferred to represent thesecond roller L2 as being driven by the roller L1, through the mediu-mof gearing, as represented in Fi 0'. 9. On the end of roller Ll is asmall gear, l1, which drives the large wheel l2 on roller L2, throughthe intermediate wheel Z3 at a slower speed. I can employ tworatchet-wheels and two pawls. They may be on the same end or on oppositeends of the machine, and in either ease they are separatelyr adjustable,so that when it is desirable to discharge more heavy material from thetrst bed without affecting the discharge from the second it is necessarysimply to change the extent ofthe motion of the pawl which works theiirst dischargingwheel, or, in case of the gearing as represented,change the size ofthe wheels. By means of this double discharge I canmake two complete sepa-rations, so as to divide the matter into threeseparated quantities or sorts in a single machine. This is obviouslyimportant in cases where there may be two kinds of metals, as, torexample, lead and zinc, mingled with the lighter earthy matter. Theheaviest material (the ore of lead) will descend from the first bed andbe discharged by the tirst discharging-wheel, while the remainingmat-ter, composed ot' the earthy matter, quartz, or other rock, and theslightly-heavier Zinc, pass oit together Jfrom the lirst bed andareseparated on the second. The second discharging means will dischargedown\ Yard the zinc, while the stony or earthy matter alone will dowover from the top ofthe second bed. The saine action is beneficial whereonly one metal is found. In such cases the first discharging means willgive pure ore; the second discharging means will deliver the richest ofthe remaining matter-that is to say, those grains where rock or earthymatter are combined; and the discharge or refuse will be merelywastethat is, quartz or earthy matter having no ore attached. With thisdouble discharge, as with the single, the form of each discharge shouldbe as shown more i'ully in Fig. l2that is to say, the front overhang andthe back shelving, so as to partially support the material. My mea-nsfor regulating the motion of the discharge-roller L is shown very fully,as applied to a single discharging-wheel, in Fig. l. 'Ihe trip-wheel Chas a radial slot, c, which carries an adjustable pin, b,- and this pincarries the pawl l, which at each reciprocation induced by thecrank-motion 'ot' the adjustable pin b takes or engages in tine teeth onthe surface of a large wheel, L3. I have represented these teeth asbeing quite coarse, but they may be graduated to any degree oi' linenessor, what is preferable in some cases, I have two or more ot' thesetoothed wheels of different-sized teeth. By this means the action of thedevice may be controlled with almost mathematical nicety in a greatvariety of intermediate positions. In my previous machines I usedv conedpulleys to graduate the speed of the dischargerollers L1L2; but thebelts were lia-ble to slip and the discharges were sudden and great, andthe entire system not perfectly reliable. My present discharge gives apositive movement to the roller and allows of delicate'adjustments, andis besides more simple a-nd compact, and is more cheaply made. Iovercome the difliculty due to the blowing voi" the air idly upwardalong the edges by obstructing the air along those lines. The gate N,which controls the discharge from the hopper M, is represented in myformer patents as merely a plane plate made sharp at its lower edge. Iprefer to retain a sharp edge at the bottom, though this is not veryimportant 5 but, whether sharpened or not, I bend the lower edge forwardso as to describe a quick curve, as shown in Figs. 2, 5, and 10. Thegranular material spreads itself on the upper side of this curve, andthe air, in consequence, is no longer liable to blow upward with eXtraforce along the face ofthe gate. I make an overhanging in the oppositedirection at the upper edge ofthe back ofthe adjustable gate K, whichcontrols the disA charge ofthe light material. In my former patents Irepresent this gate as plane on the back face or that which forms thefront boundary ot' the stratum oi' material on the ore-bed. vrlhe bendor overhanging backward near the upper edge oi' my present inventionproduces an eii'ect somewhat dii-ferent from that ot' the curve a-t theother, the receiving end ofthe bed, but agreeing' in its result. Itprevents the too violent blowing upward of the air. The extent of thecurvature and over-hanging of the gates may be varied somewhat, but Iprefer the form represented; it serves to prevent the undue blowing up.I avoid any such evil at the sides ot' the bed by providing a planeportion or strip which is unperforated along each edge.

It will be understood that the' forms and proportions ot' the parts maybe varied somewhat; but I have found that the success ofthe separationis dependent on nice conditions, particularly with some material. I'havegiven the best proportions known to me.

Vhere the bed is double the second bed may be lowered somewhat below thelevel of the iirst, and this will be an advantage with some kinds ot'material. It will also be obvious that in such case there should be ahanging partition analogous to the adjustable gate N on the front ofthehopper delivery, to compel the material which rises over the tirstdeliverygate K to` descend close to the second bed before it movesforward much thereon. I have in Fig. l0 represented the two beds as verygreatly out of level, and having a separate valve, D, for each. I preferthis construction in solne cases. Where they are on an exact level, asin Fig. 5, there should be a somewhat corresponding hanging partition,as shown.

In each of the hollow bars of the bed I is a f damper, i, (see Figs. iand 8,) which can be turned to check the force of the blast. This may,

if preferred, be mounted at the end of the bar which receives the air,and thus control the force of the blast along the entire length of thebar; or, if preferred, it may be mounted at some point so as to onlycontrol the air in the space beyond, which is less than the wholelength. Where the bed is singleand divided in two parts, as in Fig. 5, Iprefer to mount these dampers directly under the dividing-dam. All theseveral dampers are fixed in a single shaft, i', which may be turnedfrom the outside, and thus the force of the air beyond the damper may becharged at a single operation for the entire series of bars.

It is important that the force of the puff be suflicient and that thepuffs be sharply made 5 but it is not absolutely essential to successthat the valve be opened by percussion. The percussionopening is veryimportant where, from crude driving-power or from other cause, themotion is irregular, because, however slowly the machine may operate,the percussion-opening will always operate with the same suddenness orsharpness; and as the val vc shutting is effected with springs it willalways sluit with equal speed, and the variation will be all in thelength of time during which the valve remains shut, which is notimportant, except in economy of time, so long as it is sufficient toallow the material to fall after each puff. Where the speed may besteady, as when a separator is driven by a well-regulated engine, thevalve may be opened by projections on a wheel, as shown in Figs. Il and13, and the machine will be simpler. The other features of the inventionare not affected by this substitution of one opening device for anotherin different cases. Fig. I3 shows how, by means of the nuts, as shown,the extent of opening of the valve may be graduated with any desireddegree of nicety.

Some of the advantages due to certain features ofthe invention may beseparately enumerated, as follows: First, by reason of the fact that myvalve D is worked as a poppet-valve, opening and closing by a directmovement to and from its seat, and is faced with rubber or analogoussoft material, and is opened rapidly to a nicelyadjustable extent, I amenabled to receive a sharper and more perfectly-controllable action,with less friction and more endurance, than would be otherwise possible,and at the same time to work rapidly without much noise. Second, byreason of the fact that the valve l) communicates with the slendercross-chamber P', which is of very limited area and delivers the airdirectly into the hollow bars in the bed, I am able to induce a sharperaction of the puffs than is possible where, as usual, more cubical spaceis contained between the valve andthe perforations in the ore-bed.Third, by reason of my hammer F, thrown upward by the spring E to aposition close to the lever D'l and then striking the lever by itsaccumulated velocity or momentum, I am able to open the valve morerapidly than would be otherwise possible with equally simple mechanism.Fourth, by reason of the valve D opening and shutting by a directmovement without friction, and shutting by means of the adjustablespring O, I am able to shut the valve more rapidly and noiselessly thanwould be possible with otherwise equally simple mechanism. Filth, byreason of the large chamber U for the air, I receive the aircontinuously and almost uniformly through the pipe U and discharge itintermittently through the valve D. The vigor of the puffs is greaterthan would be possible without this reservoir. Sixth, by reason of theoblique back of the delivery-passage J', I retard the descent from theback portion of the ore-bed, while allowing the air to drive upward thelight matter with its full eifect, and, practically, almost arrest thedescent of the heavy matter from that position, thus devoting the backportion of the bed almost entirely to the moving upward of the lightmatter. Seventh, by reason of the overhung front II of thedelivery-passage J, I facilitate the descent of the heavy matterat theeX- treme front edge of the passage, so that the greatest proportion ofthe heavy lnatter descends at or near the extreme front of the bed,having been separated or cleaned from the light matter during itstraverse along the other portions of the bed, as specified. Eighth, byreason of my pawl and adjustable crank-pin, arranged and operating asrepresented relatively to the wheel L3 and roller L, which control thedischarge of the heavy material, I am able to adjust the ratio of thepuffing to the discharging mechanisms with any required degree ofnicety. Ninth, by reason of the duplicate delivery mechanisms, L andtheir connections, I am able to divide the material into more than twosorts at a single operation and with simple mechanism, and, by meansofthe other parts of the invention in connection therewith, to determinethe ratio of each to the other two or more sorts. Tenth, by reason ofthe mounting of the second ore-bed at a lower level than the first,where two are placed to serve in yconnection, as shown, I am able toprovide the second as well as the first with the means, as represented,for delivering the material thereon close to the ore-bed, and to employon both beds the curved gates or their equivalents for preventing theblowing up of the material at the point of entering or leaving.Eleventh, by reason of the curved bot-tom of the gate N or thedelivering edge of the hopper,I am able to resist the upward motion ofthe air through the materials along that edge and prevent any too greatdisturbance of the particles. of the overhang or backward lip orextension of the upper edge of the front gate K, I am able to resist theupward motion of the air through the material along that edge, andprevent any undue disturbance of the particles there. Thirteenth, byreason of my dampers z' i, mounted in the hollow bars of the ore-bed, Iam able to retard the passage of the air so as to control or graduateits force, and to effect this important function at a single operationin all the bars.

I claim as my invention l. The poppet-valve D, faced with soft material,operating in combination with an orc-bed and constant-blowing means, asspecified.

2. The arrangement of the valve D along the Twelfth, by reason .bottomof the slender space P, communicating directly with the hed so as towork the valve in close contact with the bed, as specied.

3. The hammer F, operating, as represented, to open the valve D bypercussive action, as set forth.

4. The spring' O, arranged and operated, as represented, relatively tothe valve D and to an ore-bed and suitable blowing means.

5. The chamber U between the pipe U and valve D, in combination with anorc-bed and blowing means, as specied.

6. The oblique back of the delivery-passage J, in combination with theore-bed I and means for puffing air up through the same, as specied.

7. rlhe overhung front H of the delivery-passage J, in combination withthe ore-hed I and means for pufng the air, as set forth.

8. In combina-tion with the bed I and means for pufling air through andfeeding forward material to be sepa-rated therein, the Wheel L3, pawl l,and adjustable crank-pin b, operating to allow a delicate adjustment ofthe velocities, as specified.

9. The employment of two or more independent delivering devices, L, andtheir connections, mounted in a single frame, the one serving todischarge the denser portions of the material which is unaffected by theother, as specified.

l0. The double ore-bed mounted at different levels, the second andlowest receiving the material thrown over from the iirst in the sainemanner as the first receives it from the elevated hopper, as and for thepurposes specified.

ll.. The curve or lip, extending forward from the lower edge of thedelivering-gate N on the hopper into and under a quantity ofthe materialon the bed, as and for the purposes specified.

1.2. The bacbvard curve or overhang of the deli v eringgate K at thefront of the ore-bed, extending into and covering a quantity oftheniaterial on the bed, as and for the purposes specitied.

13. The danipers t' fi mounted on the single shaft i', and arranged toserve within the hollow bars ofthe ore-bed, as and for the purposesherein set forth.

In testimony whereof I have hereunto set my name in presence of twosubscribing Witnesses.

S. R. KROM.

Witnesses:

THoMAs D. S'rnTsoN, A. HOERMANN. (3)

